| 摘要 |
PURPOSE:To protect a core material even against external force other than that in the longitudinal direction by wrapping the shell part of optical fibers with plastic films having prescribed tensile elastic modulus and fracture strength. CONSTITUTION:The shell part of optical fibers is wrapped with plastic films such as polyamide-hydrazide copolymer films having >=800kg/mm.<2> tensile elastic modulus in at least one direction and >=20kg/mm.<2> fracture strength. For example, quartz fibers each having 200mum diameter are clad with silicone resin, further coated with thermoplastic polyester (''Hytrel ) in 1.2mm. diameter, wound with the copolymer films each having 10mum thickness in 3 layers, and finished to 2.5mm. diameter with Hytrel. Thus, the core material can be protected even against external force other than that in the longitudinal direction. |
